# std::chrono::duration<Rep,Period>::zero

From cppreference.com
< cpp‎ | chrono‎ | duration

static constexpr duration zero(); |  | (until C++20)
static constexpr duration zero() noexcept; |  | (since C++20)

Returns a zero-length duration.

If the representation `rep` of the duration requires some other implementation to return a zero-length duration, std::chrono::duration_values can be specialized to return the desired value.

### Parameters

(none)

### Return value

Returns duration(std::chrono::duration_values<rep>::zero()).

### Example

Run this code

    #include <chrono>
    #include <ratio>

    template<typename X, typename Y>
    using dura = std::chrono::duration<X, Y>;

    static_assert
    (
        (std::chrono::hours::zero() == std::chrono::nanoseconds::zero()) &&
        (dura<short, std::nano>::zero() == dura<int, std::deci>::zero()) &&
        (dura<short, std::deca>::zero() == dura<long, std::exa>::zero()) &&
        (dura<long, std::atto>::zero().count() == dura<float, std::exa>::zero().count())
    );

    int main() {}

### See also

min [static] | returns the special duration value min (public static member function)
max [static] | returns the special duration value max (public static member function)

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